Very nice! I love the laser etched faces too.
Small world, I camped maybe a block away from that dome 
I remember reading something about it in the LEDs are Awesome facebook group, but I don’t have a link saved.
For 3D mapping, you could take the lines example, and compose that into your icosahedron. I don’t know the match off-hand, but I’m sure something could be written to programmatically generate icosahedrons of a given size.
APA102 and SK9822 have superior low brightness fidelity. Pixelblaze was designed to take advantage of that range (WS2812 support came later). They have the usual 8 bits of brightness per element like the WS2812, but also have an additional 5 bits (shared across RGB). It works out to effectively 13 bits worth of range. You don’t get the kind of posterization that happens to WS2812 at low light levels - the kind of thing where orange jumps to red as it runs out of low value bits. They have great color mixing at very low brightness levels, and can fade to black without a perceptible end.
I’d recommend you get a bit and try it out, it might just convince you it’s worth the extra wiring.
I sell LEDs in my Tindie store. Both SK9822 and RGBW SK6812 (the RGBW flavored WS2812s).